non_terminal (Java CUP Parser Generator 0.11-a-czt02-SNAPSHOT API)

java.lang.Object
- java_cup.symbol
- - java_cup.non_terminal

```
public class non_terminal
extends symbol
```
This class represents a non-terminal symbol in the grammar. Each non terminal has a textual name, an index, and a string which indicates the type of object it will be implemented with at runtime (i.e. the class of object that will be pushed on the parse stack to represent it).

Version:

last updated: 11/25/95

Author:

Scott Hudson

Field Summary

Fields
Modifier and Type	Field and Description
`protected static Hashtable<String,non_terminal>`	`_all` Table of all non-terminals -- elements are stored using name strings as the key
`protected static Hashtable<Integer,non_terminal>`	`_all_by_index` Table of all non terminals indexed by their index number.
`protected terminal_set`	`_first_set` First set for this non-terminal.
`protected boolean`	`_nullable` Nullability of this non terminal.
`protected Hashtable<production,production>`	`_productions` Table of all productions with this non terminal on the LHS.
`boolean`	`is_embedded_action` flag non-terminals created to embed action productions
`protected static int`	`next_index` Static counter to assign unique indexes.
`protected static int`	`next_nt` Static counter for creating unique non-terminal names
`static non_terminal`	`START_nt` special non-terminal for start symbol

Fields inherited from class java_cup.symbol
_index, _name, _stack_type, _use_count

Constructor Summary

Constructors
Constructor and Description

non_terminal(String nm)
Constructor with default type.

non_terminal(String nm, String tp)
Full constructor.

Constructors
Constructor and Description
`non_terminal(String nm)` Constructor with default type.
`non_terminal(String nm, String tp)` Full constructor.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add_production(production prod)` Add a production to our set of productions.
`static Enumeration<non_terminal>`	`all()` Access to all non-terminals.
`static void`	`clear()`
`static void`	`compute_first_sets()` Compute first sets for all non-terminals.
`static void`	`compute_nullability()` Compute nullability of all non-terminals.
`static non_terminal`	`find(int indx)` Lookup a non terminal by index.
`static non_terminal`	`find(String with_name)` lookup a non terminal by name string
`terminal_set`	`first_set()` First set for this non-terminal.
`boolean`	`is_non_term()` Indicate that this symbol is a non-terminal.
`protected boolean`	`looks_nullable()` Test to see if this non terminal currently looks nullable.
`boolean`	`nullable()` Nullability of this non terminal.
`int`	`num_productions()` Total number of productions with this non terminal on the LHS.
`static int`	`number()` Total number of non-terminals.
`Enumeration<production>`	`productions()` Access to productions with this non terminal on the LHS.
`String`	`toString()` convert to string

Methods inherited from class java_cup.symbol
index, name, note_use, stack_type, use_count

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - _all
```
protected static Hashtable<String,non_terminal> _all
```
    Table of all non-terminals -- elements are stored using name strings as the key
  - _all_by_index
```
protected static Hashtable<Integer,non_terminal> _all_by_index
```
    Table of all non terminals indexed by their index number.
  - next_index
```
protected static int next_index
```
    Static counter to assign unique indexes.
  - next_nt
```
protected static int next_nt
```
    Static counter for creating unique non-terminal names
  - START_nt
```
public static final non_terminal START_nt
```
    special non-terminal for start symbol
  - is_embedded_action
```
public boolean is_embedded_action
```
    flag non-terminals created to embed action productions
  - _productions
```
protected Hashtable<production,production> _productions
```
    Table of all productions with this non terminal on the LHS.
  - _nullable
```
protected boolean _nullable
```
    Nullability of this non terminal.
  - _first_set
```
protected terminal_set _first_set
```
    First set for this non-terminal.
- Constructor Detail
  - non_terminal
```
public non_terminal(String nm,
                    String tp)
```
    Full constructor.
    
    Parameters:
    
    nm - the name of the non terminal.
    
    tp - the type string for the non terminal.
  - non_terminal
```
public non_terminal(String nm)
```
    Constructor with default type.
    
    Parameters:
    
    nm - the name of the non terminal.
- Method Detail
  - clear
```
public static void clear()
```
  - all
```
public static Enumeration<non_terminal> all()
```
    Access to all non-terminals.
  - find
```
public static non_terminal find(String with_name)
```
    lookup a non terminal by name string
  - find
```
public static non_terminal find(int indx)
```
    Lookup a non terminal by index.
  - number
```
public static int number()
```
    Total number of non-terminals.
  - compute_nullability
```
public static void compute_nullability()
                                throws internal_error
```
    Compute nullability of all non-terminals.
    
    Throws:
    
    internal_error
  - compute_first_sets
```
public static void compute_first_sets()
                               throws internal_error
```
    Compute first sets for all non-terminals. This assumes nullability has already computed.
    
    Throws:
    
    internal_error
  - productions
```
public Enumeration<production> productions()
```
    Access to productions with this non terminal on the LHS.
  - num_productions
```
public int num_productions()
```
    Total number of productions with this non terminal on the LHS.
  - add_production
```
public void add_production(production prod)
                    throws internal_error
```
    Add a production to our set of productions.
    
    Throws:
    
    internal_error
  - nullable
```
public boolean nullable()
```
    Nullability of this non terminal.
  - first_set
```
public terminal_set first_set()
```
    First set for this non-terminal.
  - is_non_term
```
public boolean is_non_term()
```
    Indicate that this symbol is a non-terminal.
    
    Specified by:
    
    is_non_term in class symbol
  - looks_nullable
```
protected boolean looks_nullable()
                          throws internal_error
```
    Test to see if this non terminal currently looks nullable.
    
    Throws:
    
    internal_error
  - toString
```
public String toString()
```
    convert to string
    
    Overrides:
    
    toString in class symbol

Class non_terminal

Field Summary

Fields inherited from class java_cup.symbol

Constructor Summary

Method Summary

Methods inherited from class java_cup.symbol

Methods inherited from class java.lang.Object

Field Detail

_all

_all_by_index

next_index

next_nt

START_nt

is_embedded_action

_productions

_nullable

_first_set

Constructor Detail

non_terminal

non_terminal

Method Detail

clear

all

find

find

number

compute_nullability

compute_first_sets

productions

num_productions

add_production

nullable

first_set

is_non_term

looks_nullable

toString